1. Field of the Invention
The present invention relates to electronic circuit devices comprising at least one electronic device.
2. Description of the Prior Art
An example of known electronic circuit device comprising one or plural number of semiconductor device, such as integrated circuit (IC), is constructed as shown by FIG. 1, wherein multi-layered wiring conductor films 2 and 3 are formed by utilizing printing technology on one face of a ceramic substrate 1, the wiring conductors 2 and 3 are isolated by means of insulating layer 4 of for example SiO.sub.2, a semiconductor devices 5,5 such as ICs are bonded on the semiconductor substrate 1, and electrodes 6,6 of the semiconductor devices 5,5 are connected to the wiring conductor 2 or 3 by fine aluminum wires 7 by known wire bonding technology. In such conventional example of FIG. 1, because of having many bonding points, and theses points being bonded one by one, the manufacture necessitates many steps and takes long time in the bonding of wires. Since the bonding of the wires 7,7 are made one point by one point, the reliability is not satisfactory. Since the ceramic substrate is expensive, the resultant device becomes expensive. Furthermore, in designing the ceramic substrate, the wiring conductor pattern and arrangement of the semiconductor devices 5,5 must be made so as to shorten the lengths of the bonding wires 7,7, and therefore by means of such restriction the substrate is likely to become large.
FIG. 2 shows another example of known electric circuit device comprising one or several of semiconductor devices, fabricated according to the film carrier technology; a representative of the film carrier technology is Mini-Mod (Trade Mark of General Electric Company of USA) technology. FIG. 3 shows a section of a part of the electronic circuit device at the sectional line A--A of FIG. 2. In the Mini-Mod technology, by simultaneously bonding many beam leads to the corresponding electrodes on semiconductor device, the electronic circuit device can be made without time taking sequential bondings. The beam leads are formed on a polyimide film by coating Cu film on the polyimide film and subsequently exercising a selective etching by photolithography, and electrodes of LSI are bonded thereon by thermal compression bonding. FIG. 2 shows a part of an electronic circuit device comprising several semiconductor devices 14,14 in accordance with the Mini-Mod technology applied to multi-tip LSI. In FIG. 2, a polyimide film 8 has a specified number of openings 9,9. Beam leads 10, . . . are made by utilizing etching technology in a manner to extend from the face of the polyimide film 8 into the openings 9,9, and the beam leads 10, . . . form parts of first wiring conductors. Then insulating layer 11 of a specified pattern is formed on the polyimide film 8 and on the first wiring conductors 10,10 and second wiring conductors 12, . . . are formed on the insulating layer 11. Specified ones of the first wiring conductors 10, . . . and the specified ones of the second wiring conductors 12, . . . are connected by metal films of a part of the second wiring conductors reaching to the first wiring conductors 10, . . . through the holes 13, . . . . In the openings 9,9, a semiconductor devices 14,14 are held by bonding the beam leads 10, . . . onto the electrodes 15, . . . of the semiconductor devices 14,14.
The abovementioned Mini-Mod technology has a shortcoming that, when a large number of semiconductor devices 14, . . . are bonded to one polyimide film 8, a simultaneous bonding of them with high accuracy and high reliability is difficult, a jig to be used for the simultaneous bonding is complicated. Since the polyimide resin is very expensive, the conventional thick (about 125 .mu.m) resin film 8 used in the Mini-Mod technology is very expensive. Since the wiring conductor is rather thick (about 35 .mu.m) copper film, it is difficult to obtain a very fine pattern of the wiring conductor. Since the beam leads 10, . . . have lengths comparable with those of the fine wires in the wire-bonding technology, it is difficult to sufficiently minimize the substrate of polyimide film 8. Moreover, since the Mini-Mod technology requires the semiconductor device to have the electrodes arranged on the peripheral part thereof for bonding with the beam leads, the semiconductor device necessitates a special arrangement of the electrode pattern. Since the heat of the semiconductor device is transmitted only through the beam leads, heat dissipation of the device is not sufficient. Finally, the Mini-Mod technology is not suitable to install electronic devices heavier than the semiconductor device, since the weight of the device is supported only by the beam leads.